Absorption refrigerating apparatus



Feb. 8, 1938. G. F. ZELLHOEFER ABSORPTION REFRIGERATING APPARATUS Filed Feb. 23, 1935 I INVENTOR.

6L ENN F. ZELLHOEFER A TTORNE Y.

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Patented Feb. 8, 1938 UNITED STATES PATENT OFFICE This invention relates to improvements in absorption type of refrigerating apparatus of the character disclosed in my prior co-pending application Serial No. 736,232, filed July 20, 1934. The refrigerating apparatus so disclosed is particularly adapted to employ dichloromonofluoromethane as the refrigerant and ethyl ether of diethylene glycol acetate as the solvent. It has been found in practice that this refrigerant and solvent will carry over into the receiver from one-tenth to three-tenths per cent of solvent even though 'the gaseous refrigerant in the rec-. tlfier is chilled as low as between 110 to 100 F., and an eliminator in the form of copper mesh is used in the rectifier. Under these conditions, a refrigerating coil operating at 40 F. will carry at the outlet of the cooling coil a solution of solvent and refrigerant, and in this solution, it

has been found there is between two to three' which illustrates in diagrammatical form the type of absorption apparatus disclosed in my said co-pending application and in detail the improved apparatus for effecting this economy with the understanding that minor detail changes may be made without departing from the scope of this invention.

As this invention relates only to the means and method of liberating the refrigerant from that portion of the solution collected in the cooling coil of the apparatus, only the essential elements of the refrigerating apparatus need be described. In the apparatus illustrated in the diagram, the refrigerant and solvent form a solution in the absorber A. The solution is .con-

veyed by the pipe I from the absorber through the heat exchanger HE and by pipe Ito the heater H where the refrigerant is distilled or 4 to the expansion valve 5 connected with the manifold 6 of the cooling coil CC. The liquid refrigerant, being discharged under lower pressure in the'cooling coil CC, returns to gaseous state and in so doing absorbs'heat from the atmosphere surrounding the cooling coil. The gaseous refrigerant leaves the cooling coil through the manifold! and is conducted by the pipes 8 and 8 back to the'absorber A. The pipes 9 and 9, ill and Ill circulate cooling water through the absorber A and rectifier R and the condenser C.

As stated hereabove with the particular refrigerant and solvent specified, a portion of the solution is carried over from the rectifier and will collect in. the manifold l of the cooling coil. To separate the refrigerant and solvent forming this solution, the gaseous refrigerant and the said solution collecting in the manifold I are dis'-' charged through the pipe 8 into one end of an additional heat exchanger ll, preferably of cy- 20 lindricalform. The pipe 4, leading the liquid refrigerant from theliquid receiver R, is passed through one end of the additional heat exchange er- II and is joined to a coil l2 contained within and of less diameter than the said additional heat exchanger with the opposite end joined to the pipe 4 leading from the opposite end of the additional heat exchanger H 'to the expansion valve 5 of the cooling coil.

It has been found that the liquid refrigerant from the receiver passing through thecoil l2 of the additional heat exchanger is ordinarily at a temperature ranging from -95 F. and the solution of the refrigerant and solvent delivered from the manifold 1 into the additional heat exchanger H, in passing over the warm surface of the coil l2 will liberate nearly allof the refrigerant from the solution and the cooling effect therefrom is conserved as the refrigerant delivered through pipe l into the cooling coil is at a lower temperature than that delivered through pipe 4 into the additional heat exchanger H. In addition to the cooling effect of the liquid re-- frigerant due to the vaporization of the refrigerant from the solvent within the additional heat exchanger ll, there is also some cooling effect derived by super-heating the vaporized rerrigerant in passing, over the coil l2. Furthermore, under certain conditions, there is a tendency for a dryexpansion coil or cooling coil to flood at times, and, by the addition of this additional heat exchanger I I, connected in the manner shown to the discharge side of the cooling coil, effects the vaporization of the refrigerant in part or in toto that is flooded through the manifold I of the cooling coil. While the amount of cooling of the liquid refrigerant depends upon operating conditions and the size of the coil, it is estimated that the inclusion of the additional heat exchanger ll eifeets an economy ranging from five to twenty per cent.

What I claim is:

In an absorption refrigerating apparatus ineluding an absorber, a heater, a heat exchanger between the absorber and the heater, a cooling coil, a condenser between the heater and cooling coil, with means for passing the solution of refrigerant, and solvent through the heat exchanger into the heater and means'ior passing the refrigerant liberated from the solution from the heater through the condenser and cooling coil to the absorber while returning the solvent from which the refrigerant has been liberated the cooling coil, whereby flooding of the cooling coil is prevented and the cooling eflect produced within the chamber by the liberation of refrigerant from the solution collected therein by the passage of the refrigerant and carried over solution through the coil within the chamber reduces the temperature thereof as it leaves said coil on itsway to the cooling coil.

(51mm F. ZELLHOEFER. 

